I. Field
The following description relates generally to wireless communications, and more particularly to employing an efficient scheme for indicating system parameter(s) in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power, . . . ). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple access terminals. Each access terminal can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to access terminals, and the reverse link (or uplink) refers to the communication link from access terminals to base stations. This communication link can be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. A MIMO channel formed by the NT transmit and NR receive antennas can be decomposed into NS independent channels, which can be referred to as spatial channels, where NS≤{NT, NR}. Each of the NS independent channels corresponds to a dimension. Moreover, MIMO systems can provide improved performance (e.g., increased spectral efficiency, higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.
MIMO systems can support various duplexing techniques to divide forward and reverse link communications over a common physical medium. For instance, frequency division duplex (FDD) systems can utilize disparate frequency regions for forward and reverse link communications. Further, in time division duplex (TDD) systems, forward and reverse link communications can employ a common frequency region so that the reciprocity principle allows estimation of the forward link channel from reverse link channel.
Wireless communication systems oftentimes employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream may be a stream of data that can be of independent reception interest to an access terminal. An access terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, an access terminal can transmit data to the base station or another access terminal.
Various parameter(s) can be associated with each base station in a wireless communication system. The parameter(s) can relate to radio frame structure type, duplexing technique, cell type, unicast versus multicast operation, and so forth. For example, the base station can utilize one of two possible radio frame structures (e.g., frame structure type 1 or frame structure type 2 as set forth in the Evolved UMTS Terrestrial Radio Access (E-UTRA) specification). Further, the base station can be part of a TDD system or a FDD system. Moreover, the base station can be associated with a macro cell or a femto cell. Additionally or alternatively, the base station can be part of a unicast system or a multicast system.
Conventionally, an access terminal lacks knowledge of parameter(s) associated with a base station with which it is interacting upon initialization of a connection therebetween. For instance, upon power-up, an access terminal can begin to transmit data to and/or receive data from a particular base station. However, the access terminal can be unaware of the radio frame structure type, duplexing technique, cell type, and/or unicast/multicast operation utilized by or associated with the base station with which it is communicating.
Common techniques employed by access terminals to identify various parameter(s) associated with corresponding base stations are oftentimes inefficient and time consuming. By way of illustration, an access terminal typically effectuates acquisition by decoding information sent over a broadcast channel as well as subsequently transferred information. Thus, signals sent by the base station are commonly decoded to determine one or more of the aforementioned parameters. However, decoding of these signals can be difficult at best when such parameter(s) are unknown. According to an example, an access terminal can be unable to differentiate between use of frame structure type 1 and frame structure type 2 when employing blind cyclic prefix (CP) detection.